Magnetic inductor stack including magnetic materials having multiple permeabilities

Abstract

Provided is an inductor structure. In embodiments of the invention, the inductor structure includes a first laminated stack. The first laminated stack includes layers of an insulating material alternating with layers of a first magnetic material. The inductor structure includes a laminated second stack formed on the first laminated stack. The second laminated stack includes layers of the insulating material alternating with layers of a second magnetic material. The second magnetic material has a greater permeability than does the first magnetic material.

What is claimed is: 
     
       1. A method of forming an inductor structure in a semiconductor device, comprising:
 forming a first laminated stack including:
 forming one or more layers of an insulating material; and 
 forming one or more layers of a first magnetic material, wherein the layers of the insulating material alternates with layers of the first magnetic material; and
 forming a second laminated stack on the first laminated stack, the second laminated stack formed by: 
 forming one or more layers of the insulating material; and 
 forming one or more layers of a second magnetic material; 
 wherein the layers of the insulating material alternate with the layers of the second magnetic material; and 
 wherein the second magnetic material has a permeability that is larger than a permeability of the first magnetic material. 
 
 
 
     
     
       2. The method of  claim 1 , wherein the magnetic materials are selected from the group consisting of a Co containing magnetic material, FeTaN, and FeNi. 
     
     
       3. The method of  claim 1 , wherein the magnetic materials include a magnetic material having a relative permeability of about 500 to about 3,000. 
     
     
       4. The method of  claim 1 , wherein:
 forming the first laminated stack includes forming the first laminated stack on a substrate. 
 
     
     
       5. The method of  claim 4 , further comprising:
 forming a bottom coil between the substrate and the first laminated stack. 
 
     
     
       6. The method of  claim 5 , wherein forming the bottom coil comprises:
 forming an oxide on the substrate; 
 forming the bottom coil on the oxide; and 
 surrounding the bottom coil with additional oxide. 
 
     
     
       7. The method of  claim 5 , further comprising:
 forming a top coil above the second laminated stack. 
 
     
     
       8. The method of  claim 7 , wherein forming the top coil comprises:
 forming a hard mask above the second laminated stack; 
 forming an oxide on the hard mask; 
 forming the top coil on the oxide; and 
 surrounding the top coil with additional oxide. 
 
     
     
       9. The method of  claim 4 , wherein:
 the substrate is chosen from one of the following materials: silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, aluminum gallium arsenide, and indium gallium arsenide. 
 
     
     
       10. The method of  claim 1 , further comprising:
 depositing a third laminated stack on the second laminated stack by:
 depositing the layers of insulating material; and 
 depositing layers of a third magnetic material; wherein:
 the layers of insulating material alternate with the layers of the third magnetic material; and 
 the second magnetic material having a permeability larger than that of the third magnetic material. 
 
 
 
     
     
       11. The method of  claim 10 , wherein the first magnetic material is a same magnetic material as the third magnetic material. 
     
     
       12. The method of  claim 10 , further comprising:
 forming a top coil above the third laminated stack. 
 
     
     
       13. The method of  claim 12 , wherein forming the top coil comprises:
 forming a hard mask above the third laminated stack; 
 forming an oxide on the hard mask; 
 forming the top coil on the oxide; and 
 surrounding the top coil with additional oxide. 
 
     
     
       14. The method of  claim 1 , wherein:
 each layer of the one or more layers of the first magnetic material has a thickness of between 50 nm and 500 nm. 
 
     
     
       15. The method of  claim 14 , wherein:
 each layer of the one or more layers of the first magnetic material is deposited using vacuum deposition technologies. 
 
     
     
       16. The method of  claim 14 , wherein:
 each layer of the one or more layers of the insulating material is chosen from one of the following: silicon dioxide, silicon nitride, silicon oxynitride, magnesium oxide, or aluminum oxide. 
 
     
     
       17. The method of  claim 16 , wherein:
 each layer of the one or more layers of the insulating material is deposited using a process chosen from one of the following: PVD, CVD, PECVD, or a combination thereof. 
 
     
     
       18. The method of  claim 1 , wherein:
 each layer of the one or more layers of the insulating material has a thickness of between 1 nm and 500 nm. 
 
     
     
       19. The method of  claim 1 , wherein:
 a number of layers of insulating material is equal to a number of layers of the first magnetic material in the first laminated stack. 
 
     
     
       20. The method of  claim 1 , wherein:
 a number of layers of insulating material is equal to a number of layers of the second magnetic material in the second laminated stack.